/* ============================================
   CSS Variables
   ============================================ */
:root {
    --color-primary: #4f46e5;
    --color-primary-hover: #4338ca;
    --color-primary-light: #eef2ff;
    --color-danger: #dc2626;
    --color-danger-hover: #b91c1c;
    --color-success: #059669;
    --color-warning: #d97706;
    --color-bg: #f8fafc;
    --color-surface: #ffffff;
    --color-border: #e2e8f0;
    --color-text: #1e293b;
    --color-text-secondary: #64748b;
    --color-text-muted: #94a3b8;
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-full: 999px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 24px rgba(0,0,0,0.1);
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --transition: 0.2s ease;
}

/* ============================================
   Reset & Base
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* ============================================
   Navigation
   ============================================ */
nav {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(8px);
    background: rgba(255,255,255,0.95);
}

.nav-left a {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 6px;
}

.nav-right a {
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 0.875rem;
    font-weight: 500;
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    transition: all var(--transition);
}

.nav-right a:hover {
    color: var(--color-primary);
    background: var(--color-primary-light);
}

/* ============================================
   Layout
   ============================================ */
.container {
    width: 100%;
    max-width: 960px;
    margin: 0 auto;
    padding: 32px 24px;
}

/* ============================================
   Cards
   ============================================ */
.card {
    background: var(--color-surface);
    padding: 28px 32px;
    border-radius: var(--radius-lg);
    margin-bottom: 24px;
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
}

.card h2 {
    font-size: 1.35rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--color-text);
    letter-spacing: -0.02em;
}

.card h3 {
    font-size: 1.05rem;
    font-weight: 600;
    margin-top: 20px;
    margin-bottom: 12px;
    color: var(--color-text);
}

.card p {
    color: var(--color-text-secondary);
    font-size: 0.925rem;
    margin-bottom: 4px;
    line-height: 1.7;
}

.card hr {
    border: none;
    border-top: 1px solid var(--color-border);
    margin: 20px 0;
}

/* ============================================
   Form Elements
   ============================================ */
label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: 4px;
    margin-top: 14px;
}

input[type="text"],
input[type="email"],
input[type="password"],
input[type="number"],
input[type="file"],
textarea,
select {
    width: 100%;
    padding: 10px 14px;
    font-size: 0.9rem;
    font-family: var(--font-sans);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    color: var(--color-text);
    transition: border-color var(--transition), box-shadow var(--transition);
    outline: none;
}

input:focus,
textarea:focus,
select:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

input:disabled,
textarea:disabled,
select:disabled {
    background: #f1f5f9;
    color: var(--color-text-muted);
    cursor: not-allowed;
}

textarea {
    min-height: 100px;
    resize: vertical;
}

/* Checkbox styling */
label:has(input[type="checkbox"]) {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    cursor: pointer;
    margin-top: 12px;
}

input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
    cursor: pointer;
}

/* ============================================
   Buttons
   ============================================ */
button,
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 20px;
    font-size: 0.875rem;
    font-weight: 600;
    font-family: var(--font-sans);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    text-decoration: none;
    transition: all var(--transition);
    background: var(--color-primary);
    color: white;
    line-height: 1.4;
}

button:hover,
.btn:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

button:active,
.btn:active {
    transform: translateY(0);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: #f8fafc;
    border-color: #cbd5e1;
}

.btn-outline {
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
}

.btn-outline:hover {
    background: var(--color-primary-light);
    transform: translateY(-1px);
}

.btn-danger {
    background: var(--color-danger);
    color: white;
}

.btn-danger:hover {
    background: var(--color-danger-hover);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.8rem;
}

.btn-pill {
    border-radius: var(--radius-full);
}

.danger-btn {
    background: var(--color-danger);
    color: white;
    border: none;
    padding: 8px 14px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.8rem;
    font-weight: 600;
    font-family: var(--font-sans);
    transition: all var(--transition);
}

.danger-btn:hover {
    background: var(--color-danger-hover);
}

/* ============================================
   Button Groups
   ============================================ */
.actions {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-top: 8px;
}

/* ============================================
   Alerts
   ============================================ */
.alert {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    margin-bottom: 16px;
    font-size: 0.875rem;
    font-weight: 500;
    border-left: 4px solid transparent;
}

.alert.success {
    background: #f0fdf4;
    color: #166534;
    border-left-color: var(--color-success);
}

.alert.danger {
    background: #fef2f2;
    color: #991b1b;
    border-left-color: var(--color-danger);
}

.alert.warning {
    background: #fffbeb;
    color: #92400e;
    border-left-color: var(--color-warning);
}

/* ============================================
   Tables
   ============================================ */
.table-wrap {
    overflow-x: auto;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.875rem;
}

.result-table {
    min-width: 700px;
}

th {
    text-align: left;
    padding: 12px 16px;
    background: #f8fafc;
    font-weight: 600;
    font-size: 0.78rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--color-border);
    white-space: nowrap;
}

td {
    padding: 12px 16px;
    border-bottom: 1px solid var(--color-border);
    color: var(--color-text);
    vertical-align: middle;
}

tbody tr:last-child td {
    border-bottom: none;
}

tbody tr {
    transition: background var(--transition);
}

tbody tr:hover {
    background: #f8fafc;
}

/* ============================================
   Status Badges
   ============================================ */
.status-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: max-content;
    padding: 3px 10px;
    border-radius: var(--radius-full);
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.status-badge.pass {
    background: #ecfdf5;
    color: #065f46;
}

.status-badge.fail {
    background: #fef2f2;
    color: #991b1b;
}

/* ============================================
   Links
   ============================================ */
.link-btn {
    color: var(--color-primary);
    font-weight: 600;
    text-decoration: none;
    font-size: 0.85rem;
}

.link-btn:hover {
    text-decoration: underline;
}

/* ============================================
   Page Headers
   ============================================ */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 20px;
    margin-bottom: 24px;
}

.page-header h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.subtitle {
    color: var(--color-text-secondary);
    margin: 2px 0 0;
    font-size: 0.9rem;
}

/* ============================================
   Pagination
   ============================================ */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 20px;
    gap: 12px;
}

.page-info {
    color: var(--color-text-muted);
    font-size: 0.85rem;
}

/* ============================================
   Exam / Question Blocks
   ============================================ */
.question-block {
    margin-bottom: 20px;
    padding: 20px 24px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: #fafbfc;
    transition: border-color var(--transition);
}

.question-block:hover {
    border-color: #cbd5e1;
}

.question-block p strong {
    color: var(--color-text);
    font-size: 0.95rem;
    line-height: 1.5;
}

.option-label {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    margin: 6px 0;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--color-text);
    transition: all var(--transition);
    background: var(--color-surface);
}

.option-label:hover {
    border-color: var(--color-primary);
    background: var(--color-primary-light);
}

.option-label input[type="radio"] {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
    flex-shrink: 0;
}

/* ============================================
   Empty States
   ============================================ */
.empty-state {
    text-align: center;
    color: var(--color-text-secondary);
    padding: 48px 20px;
}

.empty-state h3 {
    margin-bottom: 8px;
    color: var(--color-text);
}

.empty-state p {
    margin-bottom: 20px;
}

/* ============================================
   Hero Section (Index)
   ============================================ */
.hero {
    text-align: center;
    padding: 60px 32px;
}

.hero h1 {
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--color-text);
    margin-bottom: 10px;
}

.hero p {
    font-size: 1.05rem;
    color: var(--color-text-secondary);
    max-width: 440px;
    margin: 0 auto 28px;
}

.hero .actions {
    justify-content: center;
}

/* ============================================
   Auth Forms
   ============================================ */
.auth-wrapper {
    max-width: 420px;
    margin: 40px auto 0;
}

/* ============================================
   Dashboard Stats
   ============================================ */
.stat-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

.stat-card {
    padding: 18px 20px;
    border-radius: var(--radius-md);
    border: 1px solid var(--color-border);
    background: #fafbfc;
    text-align: center;
}

.stat-card .stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    line-height: 1.2;
}

.stat-card .stat-label {
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-top: 4px;
}

/* ============================================
   Result Card
   ============================================ */
.result-summary {
    text-align: center;
    padding: 20px 0;
}

.result-score {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--color-text);
    letter-spacing: -0.03em;
}

.result-percentage {
    font-size: 1.1rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.result-status {
    display: inline-block;
    padding: 6px 20px;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin: 12px 0;
}

.result-status.passed {
    background: #ecfdf5;
    color: #065f46;
}

.result-status.failed {
    background: #fef2f2;
    color: #991b1b;
}

.result-meta {
    display: flex;
    justify-content: center;
    gap: 24px;
    margin-top: 16px;
    flex-wrap: wrap;
}

.result-meta span {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

.result-meta strong {
    color: var(--color-text);
}

/* ============================================
   Admin Quick Actions
   ============================================ */
.quick-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}

.quick-actions .btn {
    text-align: center;
    font-size: 0.82rem;
    padding: 12px 10px;
    background: #f8fafc;
    color: var(--color-text);
    border: 1px solid var(--color-border);
}

.quick-actions .btn:hover {
    background: var(--color-primary-light);
    color: var(--color-primary);
    border-color: var(--color-primary);
}

/* ============================================
   Config Grid
   ============================================ */
.config-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 12px;
}

.config-item {
    padding: 14px 16px;
    background: #f8fafc;
    border-radius: var(--radius-sm);
    border: 1px solid var(--color-border);
}

.config-item .config-label {
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.config-item .config-value {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--color-text);
    margin-top: 2px;
}

/* ============================================
   Exam Info Bar
   ============================================ */
.exam-info-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    background: var(--color-primary-light);
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--color-primary);
}

/* ============================================
   Question Selection (Exam Questions Page)
   ============================================ */
.filter-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.filter-count {
    font-size: 0.82rem;
    color: var(--color-text-muted);
    font-weight: 500;
    margin-left: auto;
}

.question-select-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    padding-bottom: 14px;
    border-bottom: 1px solid var(--color-border);
}

.question-select-actions .btn-sm {
    padding: 6px 14px;
    font-size: 0.8rem;
}

.selected-count {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-left: auto;
}

.question-select-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
    max-height: 520px;
    overflow-y: auto;
}

.question-select-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition), border-color var(--transition);
    margin-top: 0;
}

.question-select-item:hover {
    background: var(--color-primary-light);
}

.question-select-item.is-assigned {
    background: #f0fdf4;
    border-color: #bbf7d0;
}

.question-select-item input[type="checkbox"] {
    margin-top: 2px;
    flex-shrink: 0;
}

.question-select-body {
    flex: 1;
    min-width: 0;
}

.question-select-text {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text);
    line-height: 1.5;
}

.question-select-meta {
    display: flex;
    gap: 12px;
    margin-top: 4px;
    font-size: 0.78rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.status-badge.warning {
    background: #fef3c7;
    color: #92400e;
}

/* ============================================
   Review / Mark Sheet
   ============================================ */
.review-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 20px 32px;
}

.review-summary-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.review-label {
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-text-muted);
}

.review-value {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-text);
}

.mark-sheet-item {
    border-left: 4px solid var(--color-border);
}

.mark-sheet-item.mark-correct {
    border-left-color: var(--color-success);
}

.mark-sheet-item.mark-wrong {
    border-left-color: var(--color-danger);
}

.mark-sheet-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 10px;
}

.mark-q-num {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.mark-sheet-question {
    font-size: 0.95rem;
    font-weight: 500;
    line-height: 1.6;
    margin-bottom: 14px;
    color: var(--color-text);
}

.mark-sheet-options {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.mark-option {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    background: #f8fafc;
    border: 1px solid var(--color-border);
}

.mark-option.option-correct {
    background: #f0fdf4;
    border-color: #bbf7d0;
    color: #166534;
}

.mark-option.option-wrong.option-selected {
    background: #fef2f2;
    border-color: #fecaca;
    color: #991b1b;
}

.mark-option.option-skipped {
    background: #fffbeb;
    border-color: #fde68a;
    color: #92400e;
    font-style: italic;
}

.option-indicator {
    font-weight: 700;
    font-size: 1rem;
    width: 20px;
    text-align: center;
    flex-shrink: 0;
}

.option-tag {
    margin-left: auto;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: var(--radius-full);
    background: rgba(0,0,0,0.06);
    color: var(--color-text-secondary);
}

/* ============================================
   Pre / Code
   ============================================ */
pre {
    background: #f1f5f9;
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    font-size: 0.82rem;
    overflow-x: auto;
    border: 1px solid var(--color-border);
    line-height: 1.6;
}

ul {
    padding-left: 20px;
    margin: 8px 0;
}

ul li {
    margin-bottom: 4px;
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

/* ============================================
   Question Image
   ============================================ */
.question-image {
    max-width: 320px;
    border-radius: var(--radius-sm);
    margin: 10px 0;
    border: 1px solid var(--color-border);
}

/* ============================================
   Section Divider
   ============================================ */
.section-title {
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-text-muted);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--color-border);
}

/* ============================================
   Exam List (Dashboard)
   ============================================ */
.exam-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.exam-card {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    padding: 16px 20px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: #fafbfc;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.exam-card:hover {
    border-color: var(--color-primary);
    box-shadow: var(--shadow-sm);
}

.exam-card h3 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.exam-card-desc {
    font-size: 0.85rem;
    color: var(--color-text-secondary);
    margin-bottom: 8px;
}

.exam-card-meta {
    display: flex;
    gap: 16px;
    font-size: 0.78rem;
    color: var(--color-text-muted);
    font-weight: 500;
}

.exam-card-action {
    flex-shrink: 0;
}

.instructions-content {
    font-size: 0.95rem;
    line-height: 1.75;
    color: var(--color-text);
    white-space: pre-wrap;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 640px) {
    nav {
        padding: 0 16px;
    }

    .container {
        padding: 20px 16px;
    }

    .card {
        padding: 20px;
    }

    .hero {
        padding: 40px 20px;
    }

    .hero h1 {
        font-size: 1.5rem;
    }

    .stat-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .quick-actions {
        grid-template-columns: repeat(2, 1fr);
    }

    .config-grid {
        grid-template-columns: 1fr 1fr;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .result-meta {
        flex-direction: column;
        gap: 8px;
    }

    .exam-card {
        flex-direction: column;
        align-items: flex-start;
    }

    .exam-card-meta {
        flex-wrap: wrap;
        gap: 8px;
    }
}